Introduction: The outcomes of Jehovah's Witness (JW) patients submitted to open heart
surgery may vary across countries and communities. The aim of this study was
to describe the morbidity and mortality of JW patients undergoing cardiac
surgery in a tertiary hospital center in Southern Brazil.Methods: A case-control study was conducted including all JW patients submitted to
cardiac surgery from 2008 to 2016. Three consecutive surgical non-JW
controls were matched to each selected JW patient. The preoperative risk of
death was estimated through the mean EuroSCORE II.Results: We studied 16 JW patients with a mean age of 60.6±12.1 years. The
non-JW group included 48 patients with a mean age of 63.3±11.1 years
(P=0.416). Isolated coronary artery bypass graft
surgery was the most frequent surgery performed in both groups. Median
EuroSCORE II was 1.29 (IQR: 0.66-3.08) and 1.43 (IQR: 0.72-2.63),
respectively (P=0.988). The mortality tended to be higher
in JW patients (18.8% vs. 4.2%, P=0.095),
and there was a higher difference between the predicted and observed
mortality in JW patients compared with controls (4.1 and 18.8%
vs. 2.1 and 4.2%). More JW patients needed hemodialysis
in the postoperative period (20.0 vs. 2.1%,
P=0.039).Conclusion: We showed a high rate of in-hospital mortality in JW patients submitted to
cardiac surgery. The EuroSCORE II may underestimate the surgical risk in
these patients.

Keywords
Jehovah's Witnesses. Cardiac surgical procedures. Mortality

ABBREVIATIONS AND ACRONYMS

JW = Jehovah's Witness

HCPA = Hospital de Clínicas de Porto Alegre

SPSS = Statistical Package for Social Sciences

VAP = Ventilator-associated pneumonia

INTRODUCTION

Based on religious beliefs, Jehovah's Witness (JW) refuse blood products
transfusions. In some clinical situations, it may be both, a healthcare and an
ethical challenge. Despite the development in surgical techniques, more than 50%
of
patients receive perioperative transfusion in cardiac surgeries[1].

More recently, the data of case series[2-6] and
some controlled studies[7-10]
showed that the perioperative and postoperative prognosis of JW is similar to
those
of patients who do not have restrictions to blood products transfusions. However,
the rates of mortality and postoperative complications in patients that undergo
cardiac surgery are variable. Although clinical results are determined largely
by
sample characteristics and by the preoperative and postoperative care, assistant
teams cultural and religious factors may play a specific role in the surgical
success of these patients. Therefore, the evaluation of the cardiac surgery results
in JW patients should be evaluated in different cultural scenarios.

In Brazil, there are no studies that address local results in cardiovascular
procedures in such context. The 2010 Brazilian census[11] showed that 1,393,208 persons
(0.73% of whole population) were identified as JW. The aim of this study was to
describe the morbidity and mortality of JW patients undergoing cardiac surgery
in a
tertiary hospital center of Porto Alegre, Southern Brazil, considering only the
more
contemporary cases. We also compare the predicted mortality estimated by the
EuroSCORE II[12] in JW
patients and controls.

METHODS

The current case-control study was carried out at the Hospital de Clínicas de Porto
Alegre (HCPA), a tertiary hospital in Southern Brazil (state of Rio Grande do
Sul),
during the period from 2008 to 2016. All JW patients submitted to cardiac surgery
were selected. The patients' identification as JW occurred through surgical
schedules, bioethics consultations and keyword search in the electronic medical
records system. Three consecutive surgical non-JW controls were matched to each
selected JW patient, including only surgeries with extracorporeal circulation.

Preoperative risk of death was estimated through the mean EuroSCORE
II[12]. Death
during hospitalization, regardless of its length, was defined as hospital mortality.
The registry of at least one of the following complications was considered as
hospital morbidity: creatinine > 2 mg/dL, mechanical ventilation > 48 hours,
myocardial infarction, need for either hemodialysis or intra-aortic balloon pump,
reintervention due to bleeding, reintubation, stroke and use of antibiotics.
Definitions of active endocarditis, chronic pulmonary disease, critical preoperative
state, surgery urgency, extracardiac arteriopathy and recent myocardial infarction
(< 90 days) were the used in the EuroSCORE II study[12]. Creatinine clearance was
estimated through Cockroft-Gault formula.

Data were collected directly from the patients' electronic charts, and analyzed in
the software Statistical Package for Social Sciences (SPSS) 21.0. Qualitative
data
were reported as absolute and relative frequency; mean (± standard deviation)
or median (interquartile range) were used for quantitative variables. The comparison
of the groups was performed by Student's t-test for quantitative variables with
normal distribution, by Mann-Whitney U test, for the quantitative without normal
distribution and chi-square test for categorical variables. In situations of low
frequency, Fisher exact test was used. Normality of the distribution of each
variable was evaluated using Shapiro-Wilk test. The significance level adopted
in
all tests was 5%. The present study was submitted and approved by the local Research
Ethics Committee.

RESULTS

During the period under study, 16 JW patients were submitted to cardiac surgery at
the institution. The demographic characteristics of the whole sample are described
in Table 1. Patients were neither receiving
iron supplementation therapy nor were in critical state in the preoperative
period.

Isolated coronary artery bypass graft surgery was the most frequent surgery performed
in both groups. Extracorporeal circulation and cross-clamp times were similar
between JW and non-JW groups. Surgical characteristics data are described in Table 2.

Hospital outcomes are presented in Table 3.
There was no statistically significant difference in the rate of mortality or
morbidity, with a trend to a higher mortality in the JW group. Causes of death
were
septic (n=1), cardiogenic (n=1) and hypovolemic (n=1) shock in the JW group;
ischemic stroke (n=1) and right ventricle failure/shock (n=1) were responsible
for
the deaths in the control group. The levels of both hematocrit and hemoglobin
at
discharge were leveled between the two groups. Lengths of stay, considering both
intensive care unit and ward stay after surgery, were also similar between
groups.

The comparison of the predicted and observed mortality is shown in Figure 1. As noted, unlike non-JW group, the
observed mortality was higher than the rate predicted by mean EuroSCORE II in
the JW
group.

The need for hemodialysis in the postoperative period was significantly higher in
JW
patients, but the incidence of the other morbidities analyzed was similar between
the patients' groups. Detailed hospital morbidity per outcome is shown in Table 4. The reasons for antibiotic use were
septic shock due to central line infection (n=1) and ventilator-associated pneumonia
(VAP; n=1) in JW patients; respiratory tract infection (n=4), urinary tract
infection (n=2), surgical wound infection (n=2), VAP (n=1) and diverticulitis
(n=1)
accounted for the use of antibiotics in the non-JW group.

In this case-control study, we reported the hospital outcomes of a non-selected group
of JW that were submitted to cardiac surgery in a Brazilian tertiary center between
2008 and 2016. Outcomes and demographic variables were compared with a matched
control group as described above. The rates of hospital mortality and morbidity
were
leveled between JW and controls. However, there was a trend toward higher mortality
rate in JW than in controls (18.8 vs. 4.2%, respectively;
P=0.095). In addition, necessity of hemodialysis in the
postoperative period was greater in JW than in controls (20.0 vs.
2.1%, respectively; P=0.039). Moreover, it was observed that, in
JW, the mortality rates were higher than predicted by the EuroSCORE II. Hemoglobin
levels remained similar between groups, both preoperatively and at discharge.

Previous retrospective studies demonstrated that cardiac surgery might be performed
in JW with acceptable outcomes[2-10].
Furthermore, retrospective studies that compared mortality and morbidity rates
in JW
and controls showed leveled results between both groups[7-10]. Bhaskar et al.[9] and Pattakos et al.[10] compared outcomes of JW with a control group of
transfused patients. Marinakis et al.[7] and Stamou et al.[8] described outcomes of JW with a matched group
regardless of blood transfusion. Table 5
shows a comparison of current study with previous retrospective comparative studies.
In agreement with previous comparative studies, we observed similar levels of
hemoglobin between groups, both preoperatively and at discharge. Our results also
showed similar rate of reoperation due to excessive bleeding in JW and in controls.
However, the in-hospital mortality rate in JW in our study was higher than in
previous studies. In addition, our report is the first to demonstrate both higher
necessity of hemodialysis in the postoperative period and a trend toward higher
mortality rate in JW than in controls. Notwithstanding, our cohort is the first
report that demonstrates higher mortality rates in JW than predicted by the
EuroSCORE II in all risk strata.

Our study has several limitations. First, our sample of JW was small. However, this
is a non-selected and consecutive cohort of JW and there is no record of denial
of
cardiac surgery to any JW at our hospital. Second, surgical data were heterogeneous
between our groups: the rates of combined surgery and valve surgery were higher
in
JW than in controls. This can partly explain a trend toward higher mortality rate
among JW in our cohort. Third, this is a cross-sectional retrospective study with
all methodological limitations of such design. Therefore, our results need to
be
interpreted in a cautious and exploratory fashion.

CONCLUSION

In conclusion, our study demonstrated a high rate of in-hospital mortality in JW and
a trend toward higher mortality in JW than in controls. In addition, we observed
that in our cohort of JW the mortality risk predicted by EuroSCORE II was not
accurate: in fact, EuroSCORE II underestimated surgical risk in JW in our study.
To
our knowledge, this is the first Brazilian study to compare outcomes of heart
surgery in JW with controls.

FHV Substantial contributions to the conception or design of the work; or the acquisition, analysis, or interpretation of data for the work; drafting the work or revising it critically for important intellectual content; final approval of the version to be published

FPJ Substantial contributions to the conception or design of the work; or the acquisition, analysis, or interpretation of data for the work; drafting the work or revising it critically for important intellectual content; final approval of the version to be published

BSG Substantial contributions to the conception or design of the work; or the acquisition, analysis, or interpretation of data for the work; final approval of the version to be published

TMF Substantial contributions to the conception or design of the work; or the acquisition, analysis, or interpretation of data for the work; final approval of the version to be published

VG Substantial contributions to the conception or design of the work; or the acquisition, analysis, or interpretation of data for the work; final approval of the version to be published

MG Substantial contributions to the conception or design of the work; or the acquisition, analysis, or interpretation of data for the work; drafting the work or revising it critically for important intellectual content; final approval of the version to be published